Hi,
It depends on resolution and frame rate. For 3 1080p30 sources, it should achieve the performance in hardware encoding. You have developed an application in
Encode frames using Nvenc v4l2 - #17 by bob7421
For a quick check you can run multiple processes such as
$ _your_application_ -d /dev/video0 & _your_application_ -d /dev/video1 & _your_application_ -d /dev/video2 &
And check if it achieves target performance.